process-reset

Non-Os-Threads

Arguments:
process &optional no-unwind kill

Os-Threads

Arguments:
process &optional no-unwind

This function causes process when it next runs to
throw out to its present computation, if any, then apply its initial
function to its initial argument. The no-unwind
argument controls what happens to process' present computation, if it
has one. nil (the default) or
:unless-current cause the process to be unwound unless it
is the current process. t unconditionally
skips the unwind. Any other value is equivalent to t, causing an unconditional unwind, which will throw
out of the caller even if the process being reset is current.

The argument kill must be nil. (It is maintained only for backward
compatibility). An error is signaled if it is not.